Device for locking a cutting plate onto the body of a toolholder



July 23, 1968 G. J. VIELLET 3,393,435

DEVICE FOR LOOKING A CUTTING PLATE ONTO THE BODY OF A TOOLHOLDER FiledOct. 5, 1967 //VVE/VTOZ Guy IVIELLE-T HTTO/ZIYEVS United States PatentClaims. (or. 29-96) ABSTRACT OF THE DISCLOSURE The present inventionrelates to toolholders for machine tools of the kind in which a cuttingplate is locked to the tool body by means of a bed 'plate and a tiltableplug inserted through a hole in the body. According to this invention,the end of the plug remote from the cutting plate has an inclined faceand the plug itself has an orientation element in the form of a springwhich is matchable with a housing in the hole in the tool body. Apressure member is inserted through a tapped hole in the bottom of thetool body and has a pointed end arranged to abut against the inclinedface of the plug so as to effect the locking action.

The present invention relates to a device for locking a cutting plate tothe body of a toolholder with the aid of a bed plate connected to thebody and of a tiltable plug inserted in a hole in the latter.

It is an object of the invention to provide such a device that will beeffective in operation and simple to use.

The invention accordingly consists in the fact that the end of said plugremote from said cutting plate, has a face inclined to the general axisof said plug, said plug having mounted on its periphery an orientationelement, and wherein said hole is provided with a correspondingorientation housing for said orientation element, and a pressure meanshaving an end thereof applicable against said inclined face of said plugat a point remote from the longitudinal axis of said plug.

In order that the invention may be more readily understood, referencewill now be made to the accompanying drawings, which show one embodimentthereof, by way of example, and in which:

FIGURE 1 shows an exploded view in perspective of one embodiment of theinvention, and

FIGURE 2 shows a sectional view along line IIII of FIGURE 1, of theassembled device.

Referring now to the drawings, the body 1 of the toolholder has asteep-angled recess 2, with a triangular base 3, intended to receive abed plate 4 and a cutting plate 5.

A hole 6 is bored in the toolholder 1 substantially in the centre of thebase 3. In the upper part of the hole 6, a groove-like housing 7 isformed axially in the wall. In its lower part, remote from the base 3,the hole 6 has a tapped enlargement 8, which is more clearly visible inFIGURE 2.

The cutting plate 5 is bored at 9 and the bed plate 4 is bored at 10.This latter preferably has a diameter greater than the diameter of thehole 9, but it also has, on the side of the face of the bed plate 4intended to rest on the base 3, a constriction 11.

A plug 12 for insertion in holes 6, 10 and 9 passing through theconstriction 11, is constituted in the following manner. It has, in itsupper part a head 12a whose top is flat and whose sides are rounded.This head is connected to a cylindrical body 12b of diameter smallerthan that of the constriction 11. Below the body 12b is a shoulder 120which is extended in the axial direction "ice to form a part-cylindricalbase 12d whose diameter is greater than that of the hole 6 of thetoolholder, but smaller than that of the tapped enlargement 8.

The cylindrical base 12d is terminated by a face which is inclined withrespect to the general axis of the plug. This face is not only inclinedbut also concave as shown in FIGURE 2, in planes perpendicular to theaxis.

The shape and inclination given to the face 122 correspond to theprofile of the pointed end 13a of a set screw 13 which is screwable intothe tapped enlargement 8. The end 13a is in reality the active end ofthe screw 13 whose function will be explained later.

Along a generatrix of the plug 12 is a recess 14 which extends from thehead 12a to the base 12d. This recess is arranged to receive a resilientwire spring 15, which as a whole is concave, and'which projects at itscentre away from the body 12b. The lower end of the spring 15 is foldedover and is a reasonably tight fit at 16 in a radial hole providedtherefor.

The spring 15 is thus fixed to the plug 12, whilst retaining resilience,in its median part, under the action of a radial stress.

The use of the device of the invention is as follows:

The plug 12 is driven into the hole 6, through the tapped enlargement 8,until the shoulder 12c is arrested by the edge of the hole 6. Of course,the groove 7 of this latter must be made to correspond to the spring 15which then acts as an orientation element in the circular direction.

The bed plate 4 is placed in position and it is applied against the base3; the constriction 11 then compresses the spring 15. The cutting plate5 is positioned and the set screw 13 is screwed in until its active end13a meets the inclined face 12e of the screw-cutting tap.

Due to the constitution of the plug 12, the contact zone between theface 12e and the set screw 13 is thrown off centre on the side which isopposite, with respect to the axis of the plug 12, to the vertical wall2a of the recess 2. As soon as a tightening stress is exerted, the screw13 tilts the plug as is shown in FIGURE 2 by the angular space betweenthe axes drawn before and after tightening. The rounded side of the head12a is applied against the internal face of the hole 9 of the cuttingplate 5. This latter is held on the bed plate 4 and is strongly urgedagainst the vertical wall 2a of the recess 2.

The device of the invention gives the followin advantages: The lockingis effected by direct support of the surfaces of the plug 12 and thecutting plate, with neither sliding nor friction, both of which causewear and tear. The tightening is positive and controllable since itfollows directly from the screwing of the set screw which may bemeasured, if desired, with a torque meter. The cutting stress isdirected in the same direction as the tightening stress, to which it isadded.

On the other hand, the spring 15, compressed by the bed plate 4 holdsthe latter on the toolholder whilst is returned or replaced the cuttingplate 5.

It will be noted that the orientation of the plug 12 could be effectedwith the aid of means other than the spring 15, playing an equivalentrole from this point of view, in the same way as the set screw 13 couldbe replaced by a different pressure means which would exert an eccentricforce at the desired spot on the inclined face 122.

It will be apparent that different modifications may be given to theshape of the members and to their relative arrangements; the inventionis, therefore, not limited to the embodiment described and shown butcovers all the modifications or equivalents which would not depart fromits scope as defined by the appended claims.

I claim:

1. "A"devi'ce for locking a cutting'plate'to' the body of a toolholderwith the aid of a bed plate connected to the body and a tiltable pluginserted in a hole in the latter, wherein the end of said plug remotefrom said cutting plate, has a face inclined to the general axis of saidplug, said plug having mounted on its periphery an orientation element,wherein said hole is provided with a corresponding orientation housingfor said orientation ele-' ment, and a pressure means having an endthereof applicable against said inclined face of said plug at a pointremote from the longitudinal axis of said plug.

2. A device as claimed in claim 1, wherein the orientation elementconsists of an elongated resilient spring, disposed substantially alonga generatrix of said plug and partly inserted in a recess therein, saidspring also being able to penetrate into said orientation housing ofsaid body[ 3. A device as claimed in claim 1, wherein the end of saidhole in said body, remote from said cutting plate, is tapped to receivea pointed end of a set screw constituting said pressure means, saidpointed end being abuttable against said inclined face of said plug.

4. A device as claimed in claim 3, wherein said set screw is disposedcoaxially with said plug, and said inclined face of said plug is alsoconcave in planes perpendicular to the longitudinal axis of said plug.

5. A device as claimed in claim 2, wherein said orientation spring issituated in partin a regionvof said plug, surrounded by said bed plateand said bed-plate has a constriction to compress said spring when saiddevice is assembled.

References Cited UNITED STATES PATENTS 3,137,059 6/1964 Hertel 29963,226,797 1/1966 Hertel 2996 3,289,272 12/1966 Stier 2996 3,320,6545/1967 Lovendahl 2996 3,341,920 9/1967 Kelm 2996 3,341,921 9/1967 Weller2996 HARRISON L. HINSON, Primary Examiner.

